I will tell you why I have stayed with Dexcool. I have used it for over a decade without the slightest trace of Dex-sludge. Cooling system problems, like water pump seal failure, have been minimal over this time. Next point is subjective, I don't see the 'sparkling' cleanliness with G-05 that I see with Dexcool. Maybe it is the orange colour that makes the bare metal sparkle. I am using G-05 in one truck only, so I don't have extensive experience with it.
Sludge doesn't appear overnight. If I ever see the slightest trace of sludge in my Sierra, I will definitely investigate it and then switch over to G-05 or Peak Global Lifetime, if necessary. It is not as if we are soccer moms who never check on the coolant systems in their vehicles. I am a conservative kind of guy, Dexcool has served me very well, so I will stay with the person "who brung me to the dance"
All this said, I will only use Dexcool in vehicles that had it as factory fill. G-05 or Peak Global (and Detroit Diesel Powercool Plus for HD trucks) are my choices when I convert over from another coolant.